Firebase数据库，如何使用数据库节点的内容填充Spinner？

Question

I'm trying to fill a spinner with the contents of a node. The node is called Members and is structured like this:

Members:
-LC7n2qjCocAME4XiGuH: "ZFjiRpFJ7HgxNWBQYOhNwS6HUys2"
-LC7nSFctVUdGr6pp7k-: "XIiVCBeu5TaxMCZY7ZIsINtKKBB2"

I am trying to populate the Spinner with the data assigned to the keys. So in this case the spinner would have two entries "ZFjiRp..." and "XIiVC...". The Members node will have data added and deleted while the application runs and the spinner needs to reflect that. I figured a for loop to get the number of children of the members node to fill the spinner would work, but I don't know how to go through the node and read the data one by one.

Thanks in advance.

Answer 1

1. Get a database reference of your firebase db.
2. Attach a childeventlistener on that ref.
3. In OnChildAdded and OnChildChanged callback get the value from datasnapshot object and bind to your spinner.

Answer 2

You can do it like this:

final ArrayList<String> arrayList = new ArrayList<>();
        firebaseReference.child("Members").addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if (dataSnapshot != null) {
                    Iterator<DataSnapshot> iterable = dataSnapshot.getChildren().iterator();
                    for (Iterator<DataSnapshot> it = iterable; it.hasNext(); ) {
                        DataSnapshot dataSnapshot1 = it.next();
                        arrayList.add(dataSnapshot1.getValue(String.class));
                    }
                    //set arraylist here to spinner adapter
                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });